This proposal, submitted for NIOSH SERCA funding, involves peripheral neurodiagnostic testing to assess peripheral sensory and autonomic function utilizing vibratory and thermal computerized Quantitative Sensory Testing (QST) and the Sudomotor Axon Reflex Test (Q-SART) sweat response in 20 solvent-exposed patients and 20 non-exposed controls. Subjects with abnormal Q-SART sweat responses will also be evaluated for generalized autonomic nervous system dysfunction utilizing a standard Autonomic Nervous System (ANS) test battery. Because the subjects and controls will be recruited from participants in a funded 5-year continuation study, "Neuropsychiatric Changes in Adults Exposed to Solvents II", this proposal will provide a unique opportunity to study the effects of occupational solvent exposure on small and large peripheral sensory nerve fibers and peripheral autonomic fibers in relationship to neuropsychological and central neurophysiological function. Although there are studies which have evaluated neuropsychological parameters together with peripheral neurological testing and a few which have looked at both autonomic cardiac function and peripheral neurological status, there are no studies of solvent-exposed subjects reported which have included formal neuropsychological testing, peripheral neurodiagnostic testing, and autonomic nervous system testing in the same subjects. The specific aims of the proposed study are to: (1) determine if there is a significant difference between vibratory and/or thermal sensory thresholds in solvent exposed versus non-exposed subjects; (2) determine if there is a significant difference between Q-SART sweat responses in solvent-exposed versus non-exposed subjects; (3) ascertain the relationship between the QST and Q-SART results from this proposal and the neuropsychological-physiological parameters being measured in the same subjects in the 5-year funded continuation study; and (4) determine if solvent-exposed subjects with abnormal Q-SART responses also have autonomic dysfunction evidenced by the ANS test battery.